The researchers say their breakthrough, reported in the latest issue of ACS Nano, could apply not only to aviation but to road paving, construction, power transmission, and virtually any other industry for which chemical and physical deicing is a concern. "What we want to do is to have ice not form at all," says Joanna Aizenberg, a materials scientist and leader of the project.

When an incipient ice droplet hits a conventional surface, it spreads out and grips, becoming a base for the aggregation of more droplets and ultimately a sheet of ice. But Aizenberg's surfaces are "super-hydrophobic," which literally means "very afraid of water." They contain micron-sized geometric patterns, including posts, bricks, and other structures, that cause droplets to bounce away before they can adhere. "The key feature is that we design these structures to be nearly friction-free," Aizenberg explains. "The droplets are effectively deflected before ice formation can occur."

The nanostructures can be etched or molded into metal, rubber, or other substances. Although airplanes are an obvious destination for ice-blocking materials, Aizenberg says another important application would be in construction. The accumulation of ice on roofs can threaten their structural integrity. Roofing surfaces that shrugged off ice could avert catastrophic collapses.

Matthew Herman, a building physicist with the international engineering firm Buro Happold, says ice-repellent technology would be extremely useful for large edifices

Aizenberg and her colleagues have found that their materials resist ice accumulation until the temperature drops to about -30° C. That's far colder than nearly any industrial setting, she notes. Even at ultra-low temperatures, when the ice-repellency starts to break down, all's not lost. The ice that does form has a weak grip, requiring a small fraction—less than 10 percent—of the normal force needed to remove it from traditional surfaces. "It's very easy to strip off because it's only contacting the surface at the tips of these nanostructured features," says Aizenberg. "It can be removed just by the flow of air."